Organs of all the creatures including human grow from birth, and gradually decline with age, then, functions thereof are deactivated. When the deactivated part exceeds a certain extent, the creature dies. The process that the functions thereof are gradually declining is called aging. Skin is directly affected by surroundings and has important functions to maintain circumstance of the inner part of living bodies. Although there is not so much that all of the skin is deactivated, skin is an organ that aging symptoms such as wrinkle, liver spot, dull, slack, etc. are liable to appear thereon, and these symptoms are particularly remarkable at an exposed portion that is exposed to sun light.
When aging of the skin proceeds, protection against stimulus such as oxidative stress, etc. becomes weak, which causes disturbance of internal circumstance of the skin, whereby the skin aging further proceeds. In particular, at the exposed portion, the skin is usually exposed to potent oxidative stress such as UV rays, etc., so that progress of the skin aging is remarkable. Such a change of the skin is referred to as “photoaging”. Such a skin leads to undesirable conditions in cosmetic viewpoint that, for example, thickening of epidermis occurs or wrinkles become deep and large at the surface of the skin.
As a substance which has a reducing effect against wrinkles caused by the progress of photoaging, retinoic acid has been used for a prescription drug in the United States. However retinoic acid has potent side effects and involves problems in safety, so that it has not been admitted in Japan (see Non-Patent Literature 1). Accordingly, it has been desired to provide a wrinkle-reducing substance having high safety and sufficient effects.
On the other hand, isosorbide has been utilized in the art of medical products as a substance having high safety, and it has been known, for example, as an osmotic diuretic drug, and applied to a treating agent of Meniere's disease or an oral intraocular pressure-reducing agent, etc. Also, in the art of cosmetics, an ester and an ether of isosorbide have been utilized as a starting material of a nonionic surfactant (Patent Literature 1). However, no investigation has been conducted about a reducing effect of these substances on wrinkles.    Non-Patent Literature 1: Sachio Hamada, Gen Fukuse, “Vitamin A and its derivative as anti-wrinkle material”, “FRAGRANCE JOURNAL”, published by Fragrance Journal Ltd. on Apr. 15, 1998, vol. 26, No. 4, pp. 75-77    Patent Literature 1: Japanese Patent No. 1147661